Hydroelectric

Published on October 23rd, 2009 | by Susan Kraemer

32

Underwater Kite Harnesses Ocean Energy

October 23rd, 2009 by  

A completely new concept of underwater wave energy using a simple 7 ton kite turbine design has been developed by Minesto; which is a spinoff from the Swedish military and aircraft design firm Saab. The Deep Green underwater turbine captures the power of the ocean just like a kite in wind.

The system could generate 18 terawatthours of energy annually, enough to provide nearly 4 million British households with reliably green electricity every year. UK households now use about a third of what average US households use in energy.

Originally Saab was working on a kite design for a wind turbine, but found that the concept would actually work better in water, which is 832 times more dense than air.

The kite twirls in a repeating figure eight pattern (video) that increases the ocean velocity ten-fold. The first stage increases the relative flow speed entering a turbine. When the tide hits the wing it turns down, which creates a lift force. The kite is mounted to the ocean bed with a tether and is controlled by a rudder to gently nudge it in the desired trajectory.

According to Minesto’s website, each megawatt-worth of kite(s) would weigh 14 tons, so it would seem that each 7 ton kite is a 500 KW unit. According to CEO Anders Jansson’s estimate, these could probably produce power for somewhere between $0.09 cents and $0.20 cents per kwh.

Certainly because these are such extremely simple-tech structures they would be cost effective – costing less in materials per power produced, and costing less in transporting them to the site, in installing them and even in ongoing maintenance costs.

Almost half the potential in Europe is in British waters, with the ocean moving an average of 1 to 2 metres per second between 60 and 120 metres below the surface.

The Carbon Trust based in the UK gave early development support. Minesto’s Deep Green is now funded in part by the UK and Swedish governments, and has nearly $3 million in additional capital from parent company Saab Group, Midroc New Technology, Verdane Capital and Encubator.

With these kinds of serious investors, and such a simple and cost effective design, this could be what gets wave power to the world.

Image: Minesto Deep Green

Source: ekopolitan

More from Susan Kraemer: Journalists on Twitter

Related stories:

WaveRoller Uses Swinging Door for Underwater Wave Energy

Australia Gets Wave Power Inspired by Oil Rig

Reliable Wave Power Ensures Terrorism Protection

Hydrothermal Vents: A New Renewable Energy Source


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About the Author

writes at CleanTechnica, CSP-Today and Renewable Energy World.  She has also been published at Wind Energy Update, Solar Plaza, Earthtechling PV-Insider , and GreenProphet, Ecoseed, NRDC OnEarth, MatterNetwork, Celsius, EnergyNow, and Scientific American. As a former serial entrepreneur in product design, Susan brings an innovator's perspective on inventing a carbon-constrained civilization: If necessity is the mother of invention, solving climate change is the mother of all necessities! As a lover of history and sci-fi, she enjoys chronicling the strange future we are creating in these interesting times.    Follow Susan on Twitter @dotcommodity.



  • Water is 832 times more dense than air…wow, that`s an interesting fact! 🙂

  • Hussain Haleem

    I love the clean innovated energy system which will definitely work on Our Island as every body know 0 degree atolls. the sunny side of earth, Our government research of wind energy but I would say the ocean energy will be much batter and cheaper.
    Nice and best project
    best of luck

  • Peb0

    Ok, is it me or is there something flawed with this approach? What I mean is… how is this any different than just “funneling” the current in a way that accelerates it through and opening except in reverse??

    They’ve taken a simple concept and made it “neat”, but not derived any additional energy. They’ve just made something cool to watch but made complicated to build (or more complicated than it needs to be).

    An underwater wind-sock would do the same thing (without flying around), but cost 10% to produce and maintain.

  • Peb0

    Ok, is it me or is there something flawed with this approach? What I mean is… how is this any different than just “funneling” the current in a way that accelerates it through and opening except in reverse??

    They’ve taken a simple concept and made it “neat”, but not derived any additional energy. They’ve just made something cool to watch but made complicated to build (or more complicated than it needs to be).

    An underwater wind-sock would do the same thing (without flying around), but cost 10% to produce and maintain.

  • This is not a new concept. See http://uekus.com

    A variation on a patented idea whose original patent has expired but there are other patents active on this device.

  • This is not a new concept. See http://uekus.com

    A variation on a patented idea whose original patent has expired but there are other patents active on this device.

  • That’s it for effective energy gathering, flying foils in fluid, swooping on a thether or going to & fro along a track to spin the prop.

    Yes detritus will foul them, corrosion & wear take place, but they could be easily disconnected floated ashore & fixed.

    Sea creatures will be “sushied” so a warning sound or light system should be perfected.

  • That’s it for effective energy gathering, flying foils in fluid, swooping on a thether or going to & fro along a track to spin the prop.

    Yes detritus will foul them, corrosion & wear take place, but they could be easily disconnected floated ashore & fixed.

    Sea creatures will be “sushied” so a warning sound or light system should be perfected.

  • heather

    THE ENTERPRISE

  • heather

    THE ENTERPRISE

  • Uncle B

    As mankind grows apart from the wasteful “American Dream” borne of the “Cheap Oil Age” in America and towards a more realistic, sustainable, image, we begin to see Wave power as a practical reality, and when combined with Solar, passive a and active elements, super-insulations and other conservation designs Science makes clear, technologies make possible, Survival in reasonable comfort becomes an affordable reality for humans! Wind, in its infancy will soon compete, but for now, denser water powered means reign supreme! Tidal engines in Ireland today! Scotland too! Bay of Fundy soon a great, perpetual, Canadian resource, and once the Americans set their minds to the issue and stop chasing oil, they too can share in the New Age! Servicing these water-kites will certainly make for homeland based jobs that cannot be exported to Asians, and power for survival in the homelands too! I like it!

  • Uncle B

    As mankind grows apart from the wasteful “American Dream” borne of the “Cheap Oil Age” in America and towards a more realistic, sustainable, image, we begin to see Wave power as a practical reality, and when combined with Solar, passive a and active elements, super-insulations and other conservation designs Science makes clear, technologies make possible, Survival in reasonable comfort becomes an affordable reality for humans! Wind, in its infancy will soon compete, but for now, denser water powered means reign supreme! Tidal engines in Ireland today! Scotland too! Bay of Fundy soon a great, perpetual, Canadian resource, and once the Americans set their minds to the issue and stop chasing oil, they too can share in the New Age! Servicing these water-kites will certainly make for homeland based jobs that cannot be exported to Asians, and power for survival in the homelands too! I like it!

  • nick

    Also what is environmental impact? If there are accidents, say killing sea creatures, how bad can it get?

    It’s all out of sight.

    Nick

  • nick

    Also what is environmental impact? If there are accidents, say killing sea creatures, how bad can it get?

    It’s all out of sight.

    Nick

  • vkobaya

    The problem with this solution is the cost of maintenance. Corrosion, wear and tear and growth of marine organisms will all limit the life span of such devices. What is the estimated lifespan and cost of total replacement? The potential power is massive, but so is the cost of maintenance and replacement.

    Also what is environmental impact? If there are accidents, say killing sea creatures, how bad can it get?

  • vkobaya

    The problem with this solution is the cost of maintenance. Corrosion, wear and tear and growth of marine organisms will all limit the life span of such devices. What is the estimated lifespan and cost of total replacement? The potential power is massive, but so is the cost of maintenance and replacement.

    Also what is environmental impact? If there are accidents, say killing sea creatures, how bad can it get?

  • mr j

    looks and sounds like an underwater blender scary at best for fish comunity

  • mr j

    looks and sounds like an underwater blender scary at best for fish comunity

  • Bob

    Some people don’t like the aesthetics of wind power, this would be totally hidden from human view, which would be great.

  • Bob

    Some people don’t like the aesthetics of wind power, this would be totally hidden from human view, which would be great.

  • John B

    Kites seem like an interesting idea. I always wondered if enough power came out of it; never see data on what they can produce for real. They get a computer to fly them and maybe a little power; but I never hear the scalability and how much power and upkeep the demo units take. Plus they take a lot of sky space and you have the fun of trying to get it up in the sky…

    A water version sounds like a GREAT GREAT IDEA! Might even be usable in this form, plus we don’t use that space like we do the sky (air plane regulations.) I am concerned about how they generate power; the kites had propellers on them, these look like turbines. in this area, the air was easier– water wear and junk getting in the turbine?

  • John B

    Kites seem like an interesting idea. I always wondered if enough power came out of it; never see data on what they can produce for real. They get a computer to fly them and maybe a little power; but I never hear the scalability and how much power and upkeep the demo units take. Plus they take a lot of sky space and you have the fun of trying to get it up in the sky…

    A water version sounds like a GREAT GREAT IDEA! Might even be usable in this form, plus we don’t use that space like we do the sky (air plane regulations.) I am concerned about how they generate power; the kites had propellers on them, these look like turbines. in this area, the air was easier– water wear and junk getting in the turbine?

  • Sajit Shekhar

    This is a very bad idea.

    This thing is converting the ocean currents into the electrical energy.

    And any kind of disturbance to the ocean currents will be a disaster.

    My suggestion to you try converting the ocean waves into the electrical energy.

  • Sajit Shekhar

    This is a very bad idea.

    This thing is converting the ocean currents into the electrical energy.

    And any kind of disturbance to the ocean currents will be a disaster.

    My suggestion to you try converting the ocean waves into the electrical energy.

  • Susan Kraemer

    @giovanni, if you look at their video I linked, the thing moves very slowly – about like a whale, so that’s ok.

    I wonder though about little fish getting chopped up in that turbine head. I’ve emailed for info to see…

  • giovanni

    I wonder what impact it would have on marine biology

  • giovanni

    I wonder what impact it would have on marine biology

  • Susan Kraemer

    @giovanni, if you look at their video I linked, the thing moves very slowly – about like a whale, so that’s ok.

    I wonder though about little fish getting chopped up in that turbine head. I’ve emailed for info to see…

  • This really seems like a unique clean energy technology. But does it work? And most importantly, can it be scaled — aka — can this technology ever go commercial?

  • This really seems like a unique clean energy technology. But does it work? And most importantly, can it be scaled — aka — can this technology ever go commercial?

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